The present invention relates to a semiconductor device manufacturing technique and more particularly to a technique applicable effectively to the improvement of heat radiating performance of a semiconductor device which is assembled using a lead frame.
In a resin-sealed type semiconductor device which is assembled using a lead frame, if it carries thereon a power IC (Integrated Circuit) which generates a large quantity of heat, it is necessary to improve the heat radiating performance of the semiconductor device.
As to a heat radiation structure of a semiconductor device, a description thereof is found, for example, in Japanese Published Unexamined Patent Application No. Hei 11(1999)-284119. In this publication there is disclosed a technique in which a tub (a chip mounting portion) with a semiconductor chip mounted thereon is exposed to the surface of sealing resin to improve the heat radiating performance.